Looking Up: Good doctor makes his starry rounds

Peter Becker

Friday

May 29, 2009 at 12:01 AMMay 29, 2009 at 10:06 PM

Is there a doctor in the house? We have one represented in tonight’s evening mid-spring sky. Known better as Ophiuchus, he is really Dr. Asclepius by name, and handling snakes seem to be his game. I didn’t say he was your typical modern day physician.

Is there a doctor in the house? We have one represented in the evening mid-spring sky. Known better as Ophiuchus, he is really Dr. Asclepius by name, and handling snakes seems to be his game. I didn’t say he was your typical modern-day physician.

The constellation Ophiuchus is well up in the southeast by the time evening twilight gives way to the starry night. You have to wait until around 1:30 a.m. to see this group due south, on the meridian (the imaginary line connecting due south, passing straight overhead and leading to the spot on the sky next to the North Star). By mid-July you can see Ophiuchus due south at 10 p.m.

Unusual among constellations, Ophiuchus is associated with a second constellation that is actually broken into two; they are the two sections of the serpent that Ophiuchus is holding, according to the ancient Greek myth. These constellations are Serpens Caput (containing the head of this creature), and Serpens Cauda (ending in the tail). On the sky, the stars of Serpens Caput rise first and are seen to the right of Ophiuchus (as seen from the Northern Hemisphere). Serpens Cauda is to the left of Ophiuchus.

Among the stories connected with Ophiuchus, he is seen as a healer by the name of Asclepius, who learned that immortality could be achieved after watching a serpent bringing healing herbs to another serpent. Zeus is said to have stopped his efforts by zapping him with a lightning bolt, but honoring his good deeds with a constellation. The word Ophiuchus is Greek for “snake holder.”

I might add if Ophiuchus is adept at handling a snake, he must be good on his toes as well, for his constellation is right above the constellation Scorpius the scorpion, forever dancing above the scorpion’s starry claws but never touching them.

People’s imaginations make colorful stories among the stars and have helped pass on knowledge of the positions of the stars, as well as interest in them, for a multitude of generations before scientific discovery expanded with the invention of the telescope 400 years ago. Despite our technical advances, the 88 constellations continue to hold our interest, and the legacy of storytellers of long ago is still respected today.

Contrary to the notions of the pseudoscience of astrology, there are not 12 constellations of the zodiac. The sun and planets also pass in front of Ophiuchus.

Among the notable stars in this part of the sky, look for the two red stars close together in Ophiuchus, known as Yed Posterior and Yed Prior. Looking to us more like a pair of cat eyes staring down at us, “Yed” is Arabic for hand. These stars represent the good doctor’s grip on the reptile. “Yed Prior” is the star at right and precedes the other in its passage across the sky. Both are third magnitude.

Ophiuchus is also home to the famous Barnard’s Star, magnitude 9.5 and visible in a small telescope. This star, only six lights away, has an unusually quick proper motion, moving an entire degree every 350 years. Careful observation with a backyard telescope will reveal its motion in only a few years.

Barnard’s Star is located near a small V-shaped group of stars that was once its own little constellation, known as Poniatowski's Bull. No kidding!

A couple of notable globular star clusters lay within the constellation Ophiuchus. They are known as M10 and M12 and can be seen with binoculars.

Look nearby for the red star, Alpha Herculis, a beautiful double star in small telescopes.

Believe it or not, NASA has a spacecraft heading to Ophiuchus. Voyager I, which launched in 1977 and soared past Jupiter, Saturn, Uranus and Neptune, is now heading into interstellar space. In 40,000 years it is expected to pass less than two light years from a star in Ophiuchus. If only the car companies made such hardy vehicles!

First quarter moon is on May 30, and full moon is on June 7. Early risers can enjoy brilliant Venus, with less-bright, reddish Mars to the left, low in the eastern sky in the dawn twilight. Jupiter will be high in the southeast at that time. Saturn is high in the south-southwest in the evening.

Your comments, questions and reports may be sent to pbecker@wayneindependent.com. Peter W. Becker is managing editor at The Wayne Independent in Honesdale, Pa. He has been an amateur astronomer since the age of 12, in 1969.

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